The White Sox have been looking to trade Matt Thornton since July and are still trying to move him, according to ESPN.com’s Buster Olney (on Twitter). Before the 2011 season, the White Sox signed the left-hander to a two-year, $12MM extension that covers the 2012-13 seasons and includes a club option for 2014.

The 35-year-old posted a 3.32 ERA with 9.5 K/9, 3.2 BB/9, 0.45 HR/9 and a 48.8% ground ball rate in 59 2/3 innings this past season. Armed with a fastball that averages 96 mph, Thornton figures to draw interest this offseason, as he did last summer, especially since the free agent market doesn’t feature lefty relievers of his caliber. The Yankees, Blue Jays and Rangers are among the teams that may seek left-handed relief this offseason.

“Was mine an interim thing? If I had success, I’m sure it wouldn’t have been,” said Thornton of his abbreviated run at closer. “Obviously everyone knows what happened in the games I was in. Things just didn’t go well for me in that role.

“Maybe it was a sign I wasn’t meant to be a closer here. Over the years, I’ve done a good job of filling in as closer, and I believe in myself in that role and think I can get the job done at any given time when they give me the ball in the ninth inning. But the surge of [Chris] Sale this past year, what he did, and how good Sergio was for most of the year, this is the way it worked out.

“It’s one of those things where things weren’t going good for us and I was part of that in the back end of the bullpen,” Thornton said. “They had to make changes at the time. Just the lack of performance was the most frustrating part for me, my inability to have success that I expect myself to have, prepare and dedicate myself to have all offseason long. It’s very frustrating when you let the team down.”

If Thornton is traded, with Chris Sale moving to the starting rotation, the only lefty in the bullpen will be Will Ohman.